This disclosure relates to a protective composite material developed to resist damage or injury due to exposure to hot alkali metals, such as molten sodium. The material was specifically developed for incorporation in garments for the protection of personnel during emergency operations and rescue efforts in the vicinity of liquid-metal cooled reactors.
Typical design criteria for such a protective garment are as follows:
a. the garment must be impervious to burning alkali metals when subjected to a three second spray at a 1,000.degree. F. alkali metal bulk temperature;
b. the outer surface of the garment should be wrinkle free;
c. the garment must be capable of being put on the user with assistance in less than one minute and should be removable without assistance immediately if required;
d. the garment must permit the wearer to perform simple tasks, such as operating hand fire extinguishers, turning valve operators, climbing ladders, and rescue operation;
e. the maximum inside surface temperature of the garment should not exceed 160.degree. F. after two minutes of alkali metal burning on the surface of the suit.
The above criteria are met by a laminated composite material basically comprising an outer layer of continuous nickel foil and an inner layer of thermal insulation. The layer of nickel foil resists penetration of the molten alkali metal, while the underlying layer of thermal insulation provides the required resistance to heat transfer. This material can be adapted to various forms of protective articles for personnel or equipment, and is specifically adaptable to the construction of coats, trousers, hoods, mittens and boots to completely envelop the body of a person exposed to an environment including a possible spray of molten or burning alkali metal.